Golf putter assembly

ABSTRACT

A golf putter assembly includes a putter including a head, a display unit disposed in the putter, and a detecting unit disposed in the putter and electrically coupled to the display unit. The detecting unit is operable to detect and record a stationary starting position of a golf ball. The detecting unit is further operable to detect, during a practice swing, an instantaneous speed of the head as the head moves past the starting position, and to calculate what would be an initial speed of the golf ball if the golf ball was actually hit by the head with reference to the instantaneous speed of the head detected thereby. The detecting unit further performs control such that the initial speed of the golf ball as calculated is displayed on the display unit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a golf club. More particularly, the present invention relates to a golf putter assembly capable of determining, during a practice swing, what would be an actual golf ball response to an actual swing to thereby provide a training effect to golfers.

2. Description of the Related Art

Referring to FIG. 1, a conventional golf club 1 comprises a grip 13 that a golfer holds, a head 12 for hitting a golf ball 2, and a shaft 11 that interconnects the grip 13 and the head 12. The golfer swings the golf club 1, and strikes the golf ball 2 with the head 12 in an attempt to hit the golf ball 2 into a hole 3.

Many training implements have been disclosed that help golfers improve their game. For example, some training implements help golfers improve their putting, such as by indicating the direction the golf ball 2 must travel on a putting green to roll into the hole 3. However, such conventional implements fail to provide an indication of data associated with the amount of force required in order to successfully place the ball into the hole 3. Skillful putting is as dependent upon accurate stroke force as it is upon accurate stroke direction.

SUMMARY OF THE INVENTION

Therefore, the object of this invention is to provide a golf putter assembly that is able to determine, during a practice swing, what would be an actual golf ball response to an actual swing.

The golf club assembly of this invention comprises a putter including a head, a display unit disposed in the putter, and a detecting unit disposed in the putter and electrically coupled to the display unit. The detecting unit is operable to detect and record a stationary starting position of a golf ball, and to detect, during a practice swing, an instantaneous speed of the head as the head moves past the starting position of the golf ball. The detecting unit is further operable to calculate what would be an initial speed of the golf ball if the golf ball was actually hit by the head with reference to the instantaneous speed of the head detected thereby. The detecting unit further performs control such that the initial speed of the golf ball as calculated is displayed on the display unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:

FIG. 1 is a schematic view, illustrating a golfer using a conventional golf club;

FIG. 2 is a perspective view of a golf putter assembly according to a preferred embodiment of the present invention, illustrating the golf putter assembly on a putting green in preparation to hit a golf ball into a hole;

FIG. 3 is a fragmentary perspective view of the preferred embodiment, illustrating a head of a putter of the golf putter assembly;

FIG. 4 is a fragmentary perspective view of the preferred embodiment, illustrating a grip of the putter of the golf putter assembly; and

FIG. 5 is a schematic circuit block diagram of the preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 2, 3, and 4, a golf putter assembly according to a preferred embodiment of the present invention includes a putter 4, a display unit 5, a detecting unit 6, a user input unit 7, and a power supply unit 8.

The putter 4 includes a grip 43 that a golfer holds, a head 42 for hitting a golf ball 2, and a shaft 41 that interconnects the grip 43 and the head 42. The golfer swings the putter 4 and strikes the golf ball 2 with the head 42 in an effort to hit the golf ball 2 into a hole 3. The head 42 has a face 421 for hitting the golf ball 2, a sole 423 that is closest to the ground during play, a top surface 422 opposite to the sole 423, a back 424 opposite to the face 421, and an extension 425 that protrudes integrally and rearwardly from the back 424 and that has an upper surface 4251 that is substantially on the same plane as the top surface 422.

The display unit 5 includes a screen 51 disposed in the extension 425 of the head 42 and at least partly exposed from the upper surface 4251 of the extension 425, and keys 52 for allowing user input of data.

With additional reference to FIG. 5, the detecting unit 6 is disposed in the extension 425 of the head 42, is electrically coupled to the display unit 5, and includes a detector 61 and a controller 62. In the preferred embodiment, the detector 61 is based on MEMS (Micro-Electro-Mechanical Systems) technology (for example, the low-g linear accelerometer with model number LIS302ALB and available from STMicroelectronics). The controller 62 is able to calculate a golf ball response (described below) with reference to signals output by the detector 61 and pre-established parameters. The controller 62 subsequently performs control to display data related to the calculated golf ball response on the display 51.

The user input unit 7 is electrically coupled to the display unit 5 and the detecting unit 6, and is disposed on the putter 4. The user input unit 7 includes a switch 71 for controlling On and Off states of the display unit 5 and the detecting unit 6, and a putting green speed-setting dial 72 that allows input of a putting green speed for use by the controller 62 (described in greater detail below). In the preferred embodiment, the switch 71 and the putting green speed-setting dial 72 are disposed on the grip 43, as shown in FIGS. 2 and 4.

The power supply unit 8 is disposed in the putter 4, and is electrically coupled to the display unit 5, the detecting unit 6, and the user input unit 7. The power supply unit 8 provides electricity to the display unit 5, the detecting unit 6, and the user input unit 7. In the preferred embodiment, the power supply unit 8 includes a solar cell 81 that is disposed in the extension 425 of the head 42, and that is at least partly exposed from the upper surface 4251 of the extension 425. The solar cell 81 supplies electricity converted thereby from light to the display unit 5, the detecting unit 6, and the user input unit 7.

The rolling distance of the golf ball 2 on the putting green is a function of various factors, such as grass length, ground firmness, slope on the path to the hole 3, putting force, and wind speed and direction. The grass length and ground firmness are typically considered to determine what is referred to as “green speed.” Many golfers face difficulties in gauging the amount of force required to achieve a certain rolling distance of the golf ball 2 on a particular putting green. In order to predict golf ball rolling distance, the present invention makes use of a putting green comparison table as shown below.

The putting green comparison table was constructed as follows: A standard ball speed (e.g., 1.91 m/s) was measured using a fixed putting force on the golf ball 2 on a flat putting green. Next, the golf ball 2 was rolled on other putting greens using the standard ball speed so as to generate different rolling distances, which indicate different green speeds.

Assuming a standard ball speed (V₀) of the golf ball 2 is 1.91 m/s, and rolling distances (d) for 9 types of different putting greens of, respectively, 1.24 m, 1.55 m, 1.86 m, 2.17 m, 2.48 m, 2.79 m, 3.1 m, 3.41 m, 3.72 m, accelerations of the golf ball 2 on the different putting greens may be calculated using the following equation to thereby obtain acceleration data for the putting green comparison table:

$a = {\frac{v^{2} - v_{0}^{2}}{2d} = {\frac{0^{2} - 1.91^{2}}{2(1.24)} = {{- 1.47}\mspace{14mu} {m/s^{2}}}}}$

Putting green comparison table

Grade Rolling distance(m) Acceleration(m/s²) 1 1.24 −1.47 2 1.55 −1.18 3 1.86 −0.98 4 2.17 −0.84 5 2.48 −0.74 6 2.79 −0.65 7 3.10 −0.59 8 3.41 −0.53 9 3.72 −0.49

After the above putting green comparison table is constructed, the acceleration values are stored in the controller 62 and are used as in indication of putting green speed values for the nine different types of the putting greens. With this data stored in the controller 62, the golfer can use his or her experience to manipulate the putting green speed-setting dial 72 to select what he or she believes to be the correct putting green grade for the particular putting green that he or she is playing on. This indication of putting green speed is used as a parameter in calculating rolling distance of the golf ball 2, which is described below.

To use the golf putter assembly, the golfer first holds the grip 43 of the putter 4, places the head 42 immediately adjacent to the golf ball 2, and allows the detector 61 to detect a stationary starting position of the golf ball 2, which is recorded in the controller 62 (see FIG. 5). In some embodiments, the golfer may press the switch 71 of the user input unit 7 to activate the detector 61 to perform such detection. Next, the golfer performs a practice swing (e.g., to the rear of the golf ball 2) without actually hitting the golf ball 2. During the rearward swinging portion of the practice swing, a display value on the screen 51 is cleared. Further, during the forward swinging portion of the practice swing, an instantaneous speed (V) of the head 42 as the head 42 moves past the starting position of the golf ball 2 is detected. It is assumed for this example that the instantaneous speed (V) is detected to be 1 m/s.

The controller 62 of the detecting unit 6 is operable to calculate what would be an initial speed of the golf ball 2 if the golf ball 2 was actually hit by the head 42 with reference to the instantaneous speed (V) of the head 42 detected thereby. The controller 62 further performs control such that the initial speed of the golf ball 2 as calculated is displayed on the display unit 5. In some embodiments, the controller 62 of the detecting unit 6 calculates the initial speed of the golf ball 2 with reference to the instantaneous speed (V) of the head 42 and at least one pre-established parameter selected from the weight of the head 42, the weight of the golf ball 2, and the coefficient of elasticity of the golf ball 2. The at least one pre-established parameter may be hardwired into the controller 62 or may be input by the user, such as by manipulating the keys 52 of the display unit 5.

In the preferred embodiment, the controller 62 of the detecting unit 6 is further operable to calculate what would be a rolling distance of the golf ball 2 if the golf ball 2 was actually hit by the head 42 on the basis of the putting green speed (i.e., putting green acceleration which is proportional to putting green speed) and the instantaneous speed (V) of the head 42. The controller 62 then performs control such that the rolling distance of the golf ball 2 as calculated is displayed on the display unit 5.

The equations used to perform the calculations of the initial speed and rolling distance of the golf ball 2 are presented below. In this example, it is assumed that the pre-established parameters are as follows: the weight (M) of the head 42 is 380 g, the weight (m) of the golf ball 2 is 46 g, and the coefficient of elasticity (e) of the golf ball 2 is 0.75. Further, it is assumed that the golfer selected “5” as the grade of the putting green, to which the corresponding acceleration (a), which is obtained from the putting green comparison table, is −0.74 m/s².

$\begin{matrix} {v_{0} = {\frac{{MV}\left( {1 + } \right)}{M + m} = {\frac{380 \times 1 \times \left( {1 + 0.75} \right)}{380 + 46} = {1.56\mspace{14mu} {m/s}}}}} & {{Equation}\mspace{14mu} 1} \\ {{2D} = {\frac{v^{2} - v_{0}^{2}}{a} = {\frac{0^{2} - 1.56^{2}}{- 0.74} = {3.28\mspace{14mu} m}}}} & {{Equation}\mspace{14mu} 2} \end{matrix}$

where (v_(o)) is what would be the initial speed of the golf ball 2 if the golf ball 2 was actually hit by the head 42 of the putter 4, and (D) is what would be the rolling distance of the golf ball 2 if the golf ball 2 was actually hit by the head 42 of the putter 4. Dividing 2D by 2, we obtain D=1.64 m for this example, that is, the rolling distance of the golf ball 2 is 1.64 meters. If the golfer had selected “8” as the grade of the putting green, the calculated rolling distance of the golf ball 2 would be 2.3 m.

The detector 61 of the detecting unit 6 is further operable to determine a ground slope (θ) at the starting position of the golf ball 2. As an example, the detector 61 may determine the ground slope (θ) at the starting position of the golf ball 2 from a tilting angle of the head 42 as detected by the detector 61, that is, the detected tilting angle of the head 42 at the starting position of the golf ball 2 is assumed to approximate the ground slope (θ) at the starting position of the golf ball 2.

To provide a concrete example of how the ground slope (θ) is used in the present invention, it is first assumed that the ground slope (θ) at the starting position of the golf ball 2 is determined to be 8 degrees (θ=8°). Using the following equation, a slope putting green acceleration (a_(x)) may be calculated which increases the accuracy of calculations requiring the use of putting green acceleration (i.e., rolling distance calculations):

$a_{x} = {\frac{g\mspace{11mu} \sin \mspace{11mu} \theta}{1 + {I/{MR}^{2}}} = {\frac{g\mspace{11mu} \sin \mspace{11mu} \theta}{1 + {\frac{2}{5}{{MR}^{2}/{MR}^{2}}}} = {\frac{\left( {9.8\mspace{14mu} {m/s^{2}}} \right)\sin \mspace{11mu} 8{^\circ}}{1 + \frac{2}{5}} = {0.98\mspace{14mu} {m/s^{2}}}}}}$

where g is the acceleration due to gravity (9.8 m/s²) and I is the rotational inertia of the golf ball 2 (2/5 MR²).

By combining the slope putting green acceleration with the putting green acceleration obtained from the putting green comparison table, an accurate final putting green acceleration is obtained that takes into account several factors that may affect putting green acceleration, including the grass length and ground firmness of the putting green (i.e., the factors that determine green speed), as well as ground slope.

As an example, if we assume that the golfer has selected “2” as the grade of the putting green, which corresponds to a putting green acceleration of a=−1.18 m/s², and further assume that a downward ground slope (θ) at the starting position of the golf ball 2 is determined to be 8 degrees (θ=8°), the final putting green acceleration may be calculated as follows: a=−0.98 m/s²+(−1.18 m/s²)=−0.2 m/s². In the case where the same ground slope (θ) is an upward slope, the final putting green acceleration maybe calculated as follows: a=−0.98 m/s²+(−1.18 M/s²)=−2.16 m/s². From these results, the following equations 3 are used to calculate rolling distances as follows:

$D_{1} = {\frac{v^{2} - v_{0}^{2}}{2a} = {\frac{0^{2} - 1.56^{2}}{2\left( {- 0.2} \right)} = {6.08\mspace{14mu} m}}}$ $D_{2} = {\frac{v^{2} - v_{0}^{2}}{2a} = {\frac{0^{2} - 1.56^{2}}{2\left( {- 2.16} \right)} = {0.56\mspace{14mu} m}}}$

where D₁ is a rolling distance of the golf ball 2 when putting with the above-mentioned downward slope, and D₂ is a rolling distance of the golf ball 2 when putting with the above-mentioned upward slope.

Hence, in this case where the ground slope (θ) is used, the detecting unit 6 is operable to calculate what would be the rolling distance of the golf ball 2 if the golf ball 2 was actually hit by the head 42 with reference to the putting green speed, the instantaneous speed of the head 42, and the ground slope (θ).

Through use of the present invention as described above, the golfer is able to perform a practice swing(s) before actually hitting the golf ball 2. This allows the golfer to determine if the stroke force thought to be correct is actually a suitable stroke force for hitting the golf ball 2 into the hole 3 of the particular putting green. This can provide a good training effect, particularly to beginner golfers who may have difficulty in gauging the amount of stroke force needed for different putting situations.

While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements. 

1. A golf putter assembly, comprising: a putter including a head; a display unit disposed in said putter; and a detecting unit disposed in said putter and electrically coupled to said display unit, said detecting unit being operable to detect and record a stationary starting position of a golf ball, said detecting unit being further operable to detect, during a practice swing, an instantaneous speed of said head as said head moves past the starting position of the golf ball, said detecting unit being further operable to calculate what would be an initial speed of the golf ball if the golf ball was actually hit by said head with reference to the instantaneous speed of said head detected thereby, said detecting unit further performing control such that the initial speed of the golf ball as calculated is displayed on said display unit.
 2. The golf putter assembly of claim 1, wherein said detecting unit includes a detector for detecting the instantaneous speed of said head, said detector being based on MEMS (Micro-Electro-Mechanical Systems) technology.
 3. The golf putter assembly of claim 1, wherein said detecting unit is further operable to determine a ground slope at the starting position of the golf ball.
 4. The golf putter assembly of claim 3, further comprising a user input unit disposed on said putter and electrically coupled to said detecting unit, said user input unit allowing input of a putting green speed, said detecting unit being further operable to calculate what would be a rolling distance of the golf ball if the golf ball was actually hit by said head with reference to the putting green speed, the instantaneous speed of said head, and the ground slope, said detecting unit further performing control such that the rolling distance of the golf ball as calculated is displayed on said display unit.
 5. The golf putter assembly of claim 4, wherein said putter further includes a grip, and a shaft that interconnects said head and said grip, said user input unit being disposed on said grip of said putter.
 6. The golf putter assembly of claim 1, further comprising a power supply unit disposed in said putter, and electrically coupled to said detecting unit and said display unit, said power supply unit providing electricity to said detecting unit and said display unit.
 7. The golf putter assembly of claim 6, wherein said power supply unit includes a solar cell disposed in, and at least partly exposed from, said putter.
 8. The golf putter assembly of claim 1, wherein said display unit is disposed in said head.
 9. The golf putter assembly of claim 1, further comprising a user input unit disposed on said putter, and electrically coupled to said display unit and said detecting unit, said user input unit including a switch for controlling On and Off states of said display unit and said detecting unit.
 10. The golf putter assembly of claim 9, wherein said switch of said user input unit further allows activation of said detecting unit for detecting and recording the starting position of the golf ball.
 11. The golf putter assembly of claim 1, wherein said detecting unit calculates the initial speed of the golf ball with reference to the instantaneous speed of said head and at least one pre-established parameter selected from the weight of said head, the weight of the golf ball, and the coefficient of elasticity of the golf ball. 